THE LEECHES (HIRUDIXKA) 



^59 



54 (37) Eyes three or four pairs (rarely absent), usually one or two pairs 

 on II and two pairs at sides of mouth on I\'; no jaws, no 

 gastric ceca; genital ducts relatively simple, with small 

 atrium produced into a pair of dorsal cornua and no jK-nis; 

 testes numerous, not paired. Predaceous. 



Family Merpoudlli.idai: . . 55 



55 (56) Som 



gxu. 



ites strictly five-ringed, none of the annuli obviously enlarged 

 or subdivided. Eyes three pairs, the first largest; genital 

 pores separated by two annuli; atrial cornua simply cur\'ed; 

 vasa deferentia reaching forward to ganglion XI. 



Ilcrpohdclla punctata (Leidy) iSyc. 



The largest, bi-st known and most widely di^^tributcd 

 member of the family in North America. The color variw 

 considerably according to the amount of black i)i>s'mfni 

 present. A very active leech which feeds voraciously on 

 small worms, other leeches, and aquatic insect laivae. It 

 will take human blood when opiKjrt unity offers. Kgg 

 capsules found abundantly attached to stones, etc. 



Fig. 1008. Eerpobdella Punctata. Atrium and nciRhborinK parts 

 of reproductive organs. at, atrium; df. ductus cjacuiatoriur; 

 iXI, ganglion XI; 9 . female orifice; of, fundus of ovary; 

 ov, ovary; p, atrial horn. X 7 J. (After Moore.) 



56 (55) Annulus b obviously enlarged and subdivided 57 



57 (58) Atrial cornua spirally coiled, vasa deferentia with anterior l{X)ps 

 reaching to ganglion XI; eyes four pairs; genital orifices 

 separated by two annuli; colors plain or irregularly blotched. 



Nephelopsis obscura \'errill 1.S27. 



Fig. 1009. 



Nephelopsis obscura. Dorsal and lateral aspects of atrial 

 region. X 3- (Ori^'inal.) 



58 (57) Atrial cornua not spirally coiled, l)ut short and merely curved. 



Dina R. liianchard iSc): . . 50 



59 (62) Vasa deferentia with anterior loops reaching to ganglion XI. . 60 



60 (61) No pigmented eyes; genital pores separated by two annuli; longi- 



tudinally striped. California. . Dina atioculata'SlooTC i^S>. 



61 (60) Eyes four pairs; genital pores separated by three to three and one- 



half annuli; nearly pigmcntless. . Dina parva Moore 1Q12. 



62 (59) Vasa deferentia not extending anterior to atrium 6j 



63 (64) Eyes, three pairs; genital pores separated by three annuli; atrial 



cornua very small; pigment nearly absent. 



Dina microstoma Moore looi. 



